Question: When did Thomas Hunt Morgan stop being the chairperson at the American Association for the Advancement of Science?
Paraphrase: On what date did Thomas Hunt Morgan retire as the chairperson of AAAS?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q177681 p:P488 ?s . ?s ps:P488 wd:Q40358 . ?s pq:P582 ?value}